SerialStateLineXer t1_j58vn89 wrote

What do you mean by "obese?" The medical definition is having a BMI in excess of 30. Arguably this is not a very good definition, but it's the definition that's used. So when you say that BMI is an imperfect proxy for obesity, it's not really clear what you mean by "obesity." Are you talking about a body fat percentage threshold? Waist circumference? Waist height ratio?


SerialStateLineXer t1_j54ifch wrote

>it's self-reported. How reliable is that? (Answer: literally not at all

Self-reporting tends to introduce noise into the data set. It's far more likely to mask a real effect than to result in spurious statistical significance.

The bigger issue is that they seem to have done a lot of comparisons with no correction for multiple comparisons. This greatly increases the likelihood of a spurious finding. Although they suggest phosphoric acid as a likely factor because of the lack of association between non-cola soda and pancreatic cancer, this may just be a post-hoc rationalization for a potentially spurious finding.


SerialStateLineXer t1_j54gvr8 wrote

>Didn’t they also prove this is true of the fathers sperm? That there were differences in the sperm of obese men versus fitter men.

If true, this is almost certainly mediated by genetics to some extent, since obese men are genetically different from lean men living in the same society.


SerialStateLineXer t1_j4vcgpv wrote

One example of standards being revised due to people becoming healthier is blood lead levels. Back in the 60s, the US CDC used a threshold of 60 mcg/dL for high blood lead levels in children. Over time, as average blood lead levels come down, the threshold has been repeatedly revised downward, most recently to 3.5 mcg/dL.

Part of the reason for this, I suspect, is that back in the 60s they didn't have evidence that 3 mcg/dL was better than 5 mcg/dL because lead was so ubiquitous that they couldn't find a sample of children with levels low enough to test this hypothesis. They could tell that 80 was worse than 50, but the possibility that 3 might be better than 5 was purely hypothetical.


SerialStateLineXer t1_j4ohx65 wrote

>if they built those apartments & charged higher rent then I dont think you would see rent drop & would probably see it go up

If they could charge higher rent and still get tenants, they would. They're charging as much as the market will bear, and it still lowers prices on surrounding housing.

If they charged rent so high that nobody was willing to rent the apartments, then it would have no real effect on the price of surrounding housing, but doing that would be a tremendous waste of money.


SerialStateLineXer t1_j45h3g5 wrote

For context, the stated reason why menthol cigarettes were banned in Canada is that menthol reduces throat irritation, which is believed to be a deterrent to smoking. A recent study found that between 2016 and 2018, menthol smokers were about 50% more likely to quit after the ban than non-menthol smokers (22% vs. 15%), so it does appear to have been at least somewhat successful.

If banning menthol cigarettes is good because menthol makes smoking less unpleasant, could mandating that irritants be added to cigarettes to make smoking even more unpleasant be the next step?


SerialStateLineXer t1_j299uz0 wrote

Reasoning about cause and effect when it comes to this kind of thing is really hard, and frankly, a lot of people in epidemiology and especially journalists just aren't that good at it. Researchers get fooled by reverse causation and confounders all the time, and it's very easy for fallacious conclusions and spurious findings to get laundered into "fact" through repeated citation. This is especially likely to happen with feel-good stuff like "pets prevent Alzheimer's" or "wine prevents heart disease."

Maybe dog ownership improves health by promoting exercise, but there's very unlikely to be any real direct, clinically important biological effect of warm fuzzy feelings or reduced loneliness or whatever.


SerialStateLineXer t1_j1zo0xb wrote

>I wonder if you'd get the same results in 18 year olds, or with a more complete PGS model

You'd definitely see genetics play a much larger role. There's a huge amount of missing heritability in PGS models, i.e. they explain only a small portion of the heritability that we know is there from twin studies. As a result, studies like this underestimate the effects of genetics and overestimate the effects of SES.


SerialStateLineXer t1_j1lhxcn wrote

Reply to comment by vltamlnr in Why do teeth have nerves? by ileiskit

You're talking about dentures and not implants, right? Generally the sensory feedback you get from chewing is from the teeth transmitting forces to the periodontal tissue, not actually feeling forces in your teeth through the enamel.

Dentures disupt this process not because they don't have nerves, but because they totally change the way forces are transmitted to the periodontal tissue. I believe that root-canaled teeth and bone-borne dental implants still allow force feedback like healthy teeth do.


SerialStateLineXer t1_j1gi9nr wrote

The range is compressed by use of a log scale. The y axis is ln(papers per million people). Switzerland has five times as many papers per capita as Japan, but on a log scale it's 8.6 vs. 6.9.

Edit: This was in response to a comment expressing surprise that there was very little difference in output among wealthy countries.


SerialStateLineXer t1_j13cf9i wrote

The patients receiving the Pfizer vaccine were older, sicker, and more likely to be in nursing homes. The RR fell to 1.15 for pulmonary embolism and 1.26 for immune thrombocytopenia after controlling for this. The baseline rates were on the order of 0.06% and 0.01%, respectively, so even assuming that this is a real effect and not just a result of inadequate controls, this is roughly equivalent to an increase in absolute risk of 0.01% for PE and 0.003% for IT (doing very rough math in my head).


SerialStateLineXer t1_j0q2b5e wrote

See table 12 here. Among people age 18-64 getting a second dose of Moderna, 17% reported a fever (possibly biased downwards by people not taking temperature), over 60% reported headache, fatigue, and myalgia, and nearly 48% reported chills. This is significantly higher than for people over age 65 or for people age 18-64 getting the first dose.


SerialStateLineXer t1_j0q0ywg wrote

>The intense reactions from the initial shots means that our bodies were severely lacking in defending itself from the virus

That doesn't sound right. The mRNA vaccines contain no actual virus, so more severe side effects are caused by a stronger, not weaker, immune response. A more typical pattern is mild reaction to the first shot (when the spike protein is totally unrecognized), followed by a much more severe reaction to the second shot. Reaction to Pfizer shots was generally milder due to the lower dose.


SerialStateLineXer t1_iznopi3 wrote

It's worth noting that "early diabetes and hypertension" was driven entirely by the 25-29 age group. In older age groups, former football players had lower rates of diabetes and hypertension than the general population, and even lower rates of diabetes than former football players in the 25-29 bracket. This is possibly just a fluke, or, as you mentioned, driven by selection bias.

The more striking difference is the rates of arthritis and early onset dementia, which was large and consistent across all age groups. 2% of former football players had dementia in their 50s, but only 0.2% of the general population did. Both of these are very plausibly attributable to physical trauma experienced during play.

So I don't think there's any real mystery here. The elevated rate of diabetes and hypertension in the 25-29 group is probably spurious, while physical trauma explains the rest.


SerialStateLineXer t1_iy5h2u8 wrote

>And epigenetics can have effects for multiple generations.

In plants, yes. There's no good evidence of this happening in humans. There are a handful of studies claiming to have found evidence, e.g. with the Dutch famine, but the findings are weak and they fail to rule out alternative explanations.


SerialStateLineXer t1_iy1xqmv wrote

Evidence on this is mixed at best. While there is some evidence for a neuroprotective effect of nicotine, this appears to be offset by the negative cardiovascular effects of smoke inhalation. Even nicotine itself has a vasoconstrictive effect that could offset the neuroprotective effects seen in vitro.

Smoking does seem to be protective against Parkinson's Disease in particular, though.


SerialStateLineXer t1_ixlj7pz wrote

The claimed effect is implausibly large. The $1,000 in the title is cumulative over the first 14 years of life, not per year. Even if we assume that it's concentrated in the first five years of life, this implies that an extra $600 in income per year reduces criminal convictions in late adolescence by a third. If we assume that it's spread out over the whole 14 years, it would be a little over $200 per year.

Rather than measuring actual EITC benefits received by families, what they did was simulate the effects of variation in EITC policies between states and over time to estimate how much more or less a family would have received than the mean amount. This is highly vulnerable to confounding by, e.g., the secular decline in crime coinciding with increased funding for the EITC. This concern is limited but not eliminated by the fact that they grouped the children into 5-year birth cohorts. It is a bit suspicious that they didn't treat date of birth as a continuous variable. Furthermore, any number of other state-level factors could confound state-level differences in EITC policy.

Between the implausibly strong effect size and the methodological weaknesses, it's unlikely that they've identified a true causal effect here. There may be one, but probably not of the magnitude claimed here.